/*
 * @Description: 
 * @Version: 2.0
 * @Autor: liuwei
 * @Date: 2021-04-27 18:27:38
 * @LastEditors: liuwei
 * @LastEditTime: 2021-04-27 19:07:59
 */
class Container {
  static of(value) {
    return new Container(value)
  }
  constructor(value) {
    this._value = value
  }
  map(fn) {
    return Container.of(fn(this._value))
  }
}

class Maybe {
  static of(x) {
    return new Maybe(x)
  }
  isNothing() {
    return this._value === null || this._value === undefined
  }
  constructor(x) {
    this._value = x
  }
  map(fn) {
    return this.isNothing() ? this : Maybe.of(fn(this._value))
  }
}

module.exports = { Maybe, Container }